<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>tudou - mask</title>
  <link rel="stylesheet" href="css/mask.css">
</head>

<body>
  <!-- 土豆网鼠标经过显示遮罩: 练习显示隐藏和元素定位 -->
  <div class="box-1">
    <img src="img/news.jfif" alt="">
    <div class="mask"></div>
  </div>
  <div class="box-2">
    <!-- 使用伪元素, 优化文档树结构 -->
    <img src="img/news.jfif" alt="">
  </div>
</body>

</html>